Apparatus for sorting fertilized and unfertilized eggs



Unite States Patent [72! Inventor Jan Bures,

I Praha, Czechoslovakia [21] Appl. No. 761,402 [22] Filed Sept. 17,1968[45] Patented Oct. 13, 1970 [731' Assignee Ceskoslovenska akademie vedPraha, Czechoslovakia [32] Priority Sept. 20, 1967 [33] Caechgslovakia[3 1 1 6,699/67 [54] APPARATUS FOR SORTING FERTlLlZED AND UNFERTILIZEDEGGS 2 Claims, 2 Drawing Figs.

[52] U.S.Cl 209/73. 209/81 [51] Int. Cl B07c 5/344 [50] FieldofSearch..... 209/73, 74

75, 81 324/7 1, 71(Voltage). 61(Misc.), 61(NEP) [56] References CitedUNITED STATES PATENTS 2,102,646 12/1937 Rivenburgh 209/81X 2,149,6863/1939 Rivenburgh 209/81 2.362.774 11/1944 Romanoff t. 209/81 2,636,9254/1953 Goscoigne 324/6 1 (N mux Primary Examiner-Allen N. KnowlesAttorney Richard Low ABSTRACT: An apparatus for sorting fertilized andunfertilized eggs according to the electrical potentials arising betweenembryo and yolk during incubation. An endless conveyer with an upper andlower branch carries a plurality of pairs of electrodes, each pair beingadapted to receive an egg. in series with each pair of electrodes thereis connected through a switch a capacitor and a resistor. While the eggsmove over the upper branch, the switch is closed and the capacitorcharges to the potential picked up by the electrode. The switch isopened at the end of this branch and the capacitor stores the respectivepotential value. At the end of the lower branch over which the eggtravels in reversed position, the switch is again closed. Since turningthe egg around its long axis by 180 causes the embryo to float to theuppermost surface ofthe egg, the electrodes pick up another potentialvalue. By closing the switch a voltage difference corresponding to theembryonic potential is formed across the resistor which can be measuredwith an electrometric millivoltmeter. The resulting signals control anelectromechanical device for sorting fertilized and unfertilized eggsinto separate lines.

a te ilted Oct. 13, 1970 Sheet Patented Oct. 13, 1970 3,533,504

Sheet of 2 APPARATUS FOR SORTING FERTILIZED AND UNFERTILIZEI) EGGSBACKGROUND OF THE INVENTION l. Field of the Invention The inventionrelates to an apparatus for sorting fertilized eggs during incubationmaking use of electrical potentials produced in fertilized eggs.

2. Description of the Prior Art Whether a hens egg is fertilized andwhether its development in an Incubator proceeds normally has hithertobeen ascertained only on the fifth day of incubation bytransilluminating the egg. However, since the end of'the century it hasalready been known, as disclosed by Hermann and Gendre in I855, that thedevelopment of a chicken embryo is accompanied by characteristicelectrical potentials which can be recorded even through an intactshell, as shown by Vorontsov and Emchenko in 1947, provided a suitabletechnique is used for the measurement. In this manner it becomespossible to differentiate between a fertilized and an unfertilized eggalready after 48 hours of incubation, and to obtain a certaininformation about the speed of the development. This method has not beenemployed in poultry breeding, so far, because it is too time consuming.

It is a general object of the invention to provide an apparatus whichmakes practical use of the above findings.

Electrodes connected by means of patches soaked with a saline solutionsto the egg pick up potentials generated at the shell surface (diffusionpotentials due to'unequal mobilities of ions in the shell pores, localdifferences in shell density and in the properties of the adheringmembranes) as well as potentials arising within the eg (between yolk andegg white, between the embryo and yolk or between different parts of theembryo). As proposed by Vorontsov and Emchenko (I947) there twopotentials can be separated from each other by taking advantage of thefact that during the first days of incubation the embryo always floatsto the uppermost part of the egg. The overall potential difference V. atthe end of the initial recording period of l to 3 minutes is, therefore,equal to the sum of the contact (V and embryonic (V potentials,

After turning the egg with the electrodes through 180, the contactpotential remains unchanged but the embryonic potential graduallyreverses its polarity with respect to the electrodes as the embryoattains its position beneath the uppermost part of the shell again. Atthe end of a two-minute reversal period the potential V can thus beexpressed as 2 c e From equations (1) and (2) one obtains V V VV 2 Whileembryonic potential displays characteristic changes during development,the contact potential assumes random values ranging from 5mV to +5mVindependently of the duration of incubation. This indicates that thepotential V. approaches the value of the embryonic potential with anerror usually not exceeding 3mV. For exact measurements of the takesanother 60 seconds before the new value of the potential after turningof the egg is attained.

SUMMARY OF THE INVENTION It is a specific object of the invention toeliminate this drawback by using a simple memory element to store thevalue of potential V. until it can be compared with the potential V Toachieve this object the invention provides an apparatus comprising anendless conveyer with an upper branch and a lower branch carrying aplurality of electrode pairs. The eggs to be examined are inserted andclamped between these pairs of electrodes, one egg per pair, at thebeginning of one of the branches of the conveyer. A capacitor and aresistor are connected in series with each pair of electrodes through aswitch. The apparatus further comprises a device for opening the switchat the end of the first branch and closing it again at the end of thesecond branch. One end of the resistor is connected with one electrodesof the pair and earthed, while the other end of the resistor facing thecapacitor is connected with a contact which becomes associated with ameasuring device at the end of the second branch when the egg reachesthe end of the second branch of the conveyer. The measuring devicebecomes thus connected a-cross the resistor of the RC circuit at amoment when the switch is closed and the potential V. formed-on thecapacitor during the charging period is cornpared with the potential Vpicked up by the electrodes in the reversed position of the egg. Thecapacitor is used as a simple memory element storing the value V for alater comparison with the actual value V BRIEF DESCRIPTION OF THEDRAWING The above and other objects of the invention and its variousfeatures will be best understood from the following specification to beread in conjunction with the accompanying drawing illustrating apreferred example of embodiment.

In the drawing:

FIG. 1 illustrates a conveyer with the main elements of a measuringcircuit; and

FIG. 2 illustrates an example of arranging a pair of electrodes forinserting an egg therebetween.

In accordance with the invention the measuring time is shortened in asimple manner by using a large number of electrode pairs carried by anendless conveyer belt. Each electrode pair is connected to a capacitorstorage circuit. The differential potential is ready on an amplifierconnected with an amplitude discriminator and with an electromechanicalswitching device for placing fertilized and unfertilized eggs onseparate transport means.

The invention will now be explained in more detail referring to theaccompanying FIGS.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, theapparatus in accordance with the invention employs a conveyer 4 whichmay be of the belt or chain type, or any other suitable construction.The upper and lower branch of this conveyer extend in an approximatelyhorizontal position. On the conveyer there is provided a plurality ofelectrodes 1, 2 forming pairs of electrodes between which an egg can beclamped. At the beginning of one branch of the conveyer 4 there is anegg inserting device 112 where eggs 3 to be tested are placed betweenthe electrodes 11, 2.

FIG. 2 shows an example of embodiment of a pair of electrodes for thispurpose. This embodiment employs a yoke 5 made from an electroinsulatingmaterial carrying the electrodes l, 2. These electrodes are convenientlyconstructed as nonpolarizable Ag-AgCl electrodes. Each of the pairs ofelectrodes l, 2 is connected through a switch 6 in series with an RCcircuit comprising a capacitor 7 and a resistor 8. The electrode 2 andone of the leads of resistor 8 are grounded,

' v together with the conveyer 4. The second lead of the resistor is Inthe arrangement illustrated in FIG, 1 the upper branch of the conveyer 4passes first through the egg inserting device 12 in which eggs areplaced between the electrode pairs 1, 2, one egg per electrode pair.During the entire time in which an egg is on the upper branch of theconveyer 4; a circuit which includes the grounded conveyer 4, theelectrode 2, the egg 3, the electrode 1, the closed switch 6, thecapacitor 7 and the resistor 8, is closed.

The speed at which the conveyer 4 moves and its length are arranged sothat there is sufficient time for the potential V of the egg 3 to becomestabilized. Capacitor 7 becomes charged to the potential V, of the egg3. As soon ,as the egg reaches the end of the upper branch of theconveyer 4, the switch 6 is opened. After the egg 3 has reached thelower branch of the conveyer, its position is turned through 180 incomparison with the preceding position on the upper branch of theconveyer 4. Electrode 2 is now in contact with the upper surface of theegg 3, and electrode 1 is in contact with the lower surface. ln thisposition and with the switch 6 opened, the egg travels on the lowerbranch of the conveyer 4. During this time, the embryo becomes againstabilized in its new position, and there appears on the electrode apotential differing from the previous potential when the egg travelledon the upper branch.

Close to the entry of the sorting device 11 the contacts of the switch 6are again closed, and the contact 9 is connected to the measuring device10. Thus, electrical current begins to flow through the resistor 8 ofthe RC circuit 7, 8, and the electrometric device 10 records the voltagedrop produced across the terminal of resistor 8 which correspond to thepotential difference V. V If the egg was fertilized, a rather largevoltage drop can be recorded. After amplification, the obtained pulse isintroduced into an amplitude discriminator. if the pulse voltage exceedsa predetermined threshold value the egg is considered to have beenfertilized, and the electromechanical switching device of the transportpath in the sorting device 11 places the egg which just leaves theconveyer 4 on a nonilon the other hand, due to the fact that measurementis accomplished in two positions differing by any interfering voltagesproduced by nonuniformities of the shell of the egg, or for some otherreasons, are balanced so that the operation of the apparatusiscompletely reliable.

lclaim:

l. An apparatus for sorting fertilized and unfertilized eggs I usingelectrical potentials developed in fertilized eggs during incubation,comprising:

an endless conveyer with an upper and a lower branch;

a plurality of pairs of electrodes, each adapted to receive an egg heldat opposite sides by the two electrodes;

switch contacts;

one of the switch contacts connected with one electrode of the pair ofelectrodes and the other contact connected with a combination of acapacitor and a resistor;

means for opening the contacts of the said switch at the end of theupper branch;

means for closing the contacts of the said switch at the end of thelower branch;

a third separate contact connected with the end of the resistor facingthe capacitor and adapted to contact a measuring device so as to bringit in connection across said resistor. I

2. An apparatus as claimed in claim 1, comprising a sorting devicecontrolled by signals from said measuring device.

